Combined reproducing and recording device



Sept. 3, 1935. R, DALLY 2,013,2U1

COMBINED REPRODUCING AND RECORDING DEVICE Original Filed Oct. 29, 1951REPAODucE' 3 w 3 zwm- Patented Sept. 3, 1935 COMBINED REPRODUCING ANDnaooanme DEVICE Roy Dally; Racine, Wis., assignor to Webster ElectricCompany, Racine, Wis., a corporation the reproduction and recording ofsound of Wisconsin Original application October 29,1931, Serial No.571,727, now Patent No. 1,902,950, March 28,

1933, Serial No. 659,644

Divided and thisapplication March 6,

4 Claims. (01. 119-10041);

The present invention relates to, combined reproducing and recordingdevices of the type ,commonly called ,pick-ups, and is particularly,uconcernedv ri'th the provision of an improved pick-up which is adaptedto be used for both on ex isting radio receivers. I

The present applicationis a division of my prior application, Serial.No. 571,727, filed October 29, 1931, now Patent No. 1,902,950, grantedMarch 28, I933, on Combined reproducing and record ing devices, whichparent applicationrelates to the complete apparatus used in recordingandreproducing. The present application includes claims on subject-matterheld divisible fromv the claims ofthe parent application, and relates tothe pick-up unit per se.

lliodern radio receivers usually have an audio frequency amplifierwhichis .suitable for record I Q6" reproducing or recording when properly.coupled "to the necessary apparatus. For reproduction, a pick-up of afairly highimpedance is required, such as, for example, a pick-up havingabout five thousand of wire, and the pickcoupled directly to the gridcircuit of the detector tube, or if the audio amplifier includes 'morethan one stage it may be connected to the tube following the detector,or it may be coupledto the primary of one of the audio transformers usedin the radio receiver.

For the purpose of the present description, e'i'ther'one of these modesof connection may be considered as-a connection to the input, side of"the amplifier" or to the input side of a per- So long as the pick-uphas a fairly high impedanceit is not necessary to add any additionalequipment to the amplifier in order to reproduce records, other than thepick-up itself. 'If, on

{the other hand, a pick-up of low impedance is used, in order'toi securesatisfactory results, it

is necessary to couple the pick-up to the amplifier through a high ratiotransformer. This involves additional expense and usually results in alow efficiency, and it is therefore desirable to use for reproductionpurposes apick-uphav ing a highimpedance, coupled directly to the "gridcircuit of oneof the audio amplifier tubes.

For the purpose of recording or cutting records, the same high impedance'pic'k-upmay be used "with fair results when coupled to the amplifieroutput tube or tubes, through the proper type of transformer. Here againa special transformer isrequired if it is desired to utilize the samehigh impedance pick-up reproducing. V

Since modern receivers are designed to operate a dynamic speaker, havinga very low voice coil impedance, it would be possible to use the voicecoil winding of the output transformer only if the pick-up Winding has averylow impedance comparable with the speaker voice coil.

When the pick-up is used as a cutter, it is esfor both recording and,sentially a powerdriven device and quite sirnilar to the speaker itselfin this respect, and a more ideal and efiic'ient arrangement would beattained if the cutterimpedance were relatively low, or as low in valueas that of the speaker voice coil; A cutter impedance coil of such a lowvalue could be coupled to the output transformer secondary, replacingthe speaker and recording could 'be accomplished under more. nearlyideal conditions without the necessity for additional equipment. Forexample, the impedance of the low'impedance winding with the circuit ofthe high impedance coil open, was made about twelve and a half ohms witha certain speaker.

It will thus be observed that the ideal -re-, quirements for a simplereproducer. are inconsistent with the ideal requirements for a simplerecorder in so far as the impedance is concerned and the ordinaryreproducers and recorders cannot be utilized interchangeably without theliecessity for'additional equipment which increases the expense anddecreases the efiiciency of the device.

One of the objects of the present invention is the provision of animproved pick-up which is also adapted to beutilized for recordingwithout the necessity'for' providing additional equipment to adapt the.device for either of its functions.

Anotherobject is the provision of an improved recording device which isalso adapted to be utilized for reproduction without the necessity forproviding additional equipment, such as transformers or the like.

Another objectis the provision of an improved combined reproducing andrecording device, which is adapted to be used with modern radioreceivers without the necessity for providing special equipment tofadapt the radio receiver to the use of the reproducer or recordingdevice. Another object is the provision of an improved reprcducing andrecording device which'is-more eflici'ent than the devices of the priorart, in

which the same pick-up maybe utilized for either reproductionor-recording by merely switching different parts of the pick-up intocircuit.

' Other objects and advantages of the invention will be apparent fromthe following description, and from the accompanying drawing, in whichsimilar characters of reference indicate similar parts throughout theseveral views.

Referring to the single sheet of drawing:

Fig. l is a diagrammatic view of the apparatus and circuits required forone embodiment of my invention;

Fig. 2 is a similar diagrammatic view of the apparatus and circuits foranother embodiment of the invention;

Fig. 3 is a fragmentary View in partial section of a combined pick-upand reproducer of the type which may be used in either Fig. 1 or Fig. 2.

Referring to Figs. 1 and 2, the present apparatus preferably includesthe combined reproducer and recorder I0, and amplifier I aswitchingarrangement l2, a microphone I3, and a speaker l4. Any type of suitableamplifier, speaker or microphone may be utilized, and therefore theseelements are merely shown diagrammatically.

The pick-up is preferably of the type shown in Fig. 3, provided with asupporting casing 5|, a permanent magnet 52 having pole pieces 53, astylus 54, and coils 55. The stylus 54 is movably mounted, being carriedby the armature 56, which is preferably supported upon knife edges andall of the details of the present pick-up, except the coils, may be madesubstantially the same as that disclosed in the application of WilliamH. Hutter, Serial No. 488,243, filed October 13, 1930 now Patent No.1,934,857, granted Nov. 14, 1933.

The present pick-up is distinguished by the provision of separatewindings or separate taps for a common winding, for providing windingshaving a proper impedance for both the functions recording andreproducing most efliciently, and without the necessity for additionalapparatus.

Thus, in Fig. 1, the winding |5 which is represented as a longerwinding, is a winding of high impedance adapted to be used without thenecessity for transformers when directly connected to the input side ofthe amplifier ID. The high impedance winding I5 is preferably connectedbya conductor Hi to a fixed contact while the other side of the highimpedance winding I5 is connected by a conductor I8 to a fixed contactl9.

The pick-up also includes a low impedance winding 20 having an impedancecomparable to the impedance of the voice coil of the speaker l4, and oneterminal of the low impedance coil 20 is connected by conductor 2| to a.fixed contact 22. The other terminal of the low impedance coil 20 isconnected by conductor 23 to fixed contact 24. The microphone I3 has itsterminals connected by conductors 25, 2 6 to fixed contacts 21, 28,respectively. The speaker M has its terminals connected by conductors29, 30 to fixed contacts 3|, 32, respectively.

The input side of the amplifier l has'its terminals connected byconductors 33, 34 to the movable contact arms 35, 36, respectively. Theoutput terminals of the amplifier II are connected by conductors 31, '38to the movable contact arms 39, 48, respectively. All of the contactarms 35, 36, 39 and 4B are preferablyjoined by an insulating member 4|so that they may be simultaneously actuated by the same actuating member42.

The switch is also preferably of the snap type, adapted to move quicklyfrom one position to the other, and adapted to be positively secured ineither of its positions. For this purpose, the insulating member 4| hasbeen illustrated with a pair of grooves 43, 44 adapted to be engaged bya spring pressed ball 45. The switch is also preferably provided witharrows 46 and appropriate indicia for indicating the functions of thedevice in the different switch positions, such as Reproduce and Record.When the switch I2 is in the position of Fig. 1, it has been moved tothe recording position, and when the switch is moved to the left in Fig.1, it is moved into the reproducing position.

Refcrring to Fig. 2, this is another modification in which thereproducer is provided with a single coil 4! having a plurality of taps.The end taps l6 and 23 may be considered the same as the conductorspreviously described in connection with the device of Fig. 1. The centertap 48 performs the functions of both the conductors I8 and 2| ofFig. 1. The tap 4B is connected to windings 41 in such manner that theupper winding 49 is the high impedance winding for reproduction, whilethe lower winding 50 is the low impedance winding for recording.

The operation of the present recording and reproducing device is asfollows: When the switch I2 is in the position of Fig. 1, or that ofFig. 2, the low impedance winding 20 or 50 is connected in circuit withthe microphone l3, and the circuit may be traced from the microphone tothe amplifier as follows: I3, 25, 21, 36, 34, 33, 35, 28, 26, IS. Thecircuit may be traced from the amplifier to the recorder as follows: 38,40, 24, 23, 2|), 2|, 22, 39, 31,

The microphone I3 is thus connected to the amplifier and the lowimpedance coil 20 is connected to the output side of the amplifier insuch manner as most efiiciently to effect the recording of sound withoutthe necessity for using intermediate transformers or other devices whichreduce the efficiency. The low impedance coil 20 is thus substituted forthe voice coil of the speaker |4. V

When the switch I2 is moved to the left in Fig. 1 or Fig. 2 themicrophone and low im-' pedance coil are cutout and the speaker l4 andhigh impedance coil I are cut into the circuit. Under these conditions,the circuit may be traced from the high impedance coil I5 to theamplifier, as follows: |5, |8, Hi, 36, 34, 33, 35, l1, l6, IS. Thecircuit may be traced from the amplifier to the speaker M as follows:31, 39, 3|, 29, I4, 30, 32, 40, 38, The speaker is thus connected incircuit .with the amplifier and the high impedance coil of the pick-upis substituted for the low impedance ,coil for the purpose ofreproduction.

It will thus be observed that the present device may be used forreproductionand for re-, cording without the necessity for usingintermediate transformers, and the present pick-up may be ideallyadapted for both reproduction and recording. Thepick-up may thus beattached to existing radio receivers with a minimum amount of expenseand labor, and the present device is more adaptable and convenientlyapplied than the devices of the prior art.

Having thus described my invention, what I claim is new and desire tosecure by Letters Patent of the United States, is:

1. A combined reproducing and recording device, comprising a permanentmagnet, a stylus and an armature movably' supported with respect to saidmagnet, a-low impedancecoil adapted -to be utilized for recording, and ahigh impedance coil adapted to be utilized duction.

2. A combined reproducing and recording device, comprising a permanentmagnet, a stylus and an armature movably supported with respect to saidmagnet, a coil having a low impedance for reprosection for recording andhaving a high impedance section for reproduction, and taps connectingwith said low impedance and high impedance sections for selective use ofthe sections of said windings.

3. A combined reproducer and recorder comprising a permanent magnet, astylus and an armature movably supported with respect to said forrecording, said low impedance coil having its electrical characteristicssuitable for substitution for a speaker, and a high impedance coiladapted to be utilized for the reproduction.

4. A combined reproducing and recording device comprising a permanentmagnet, a-stylus and an armature movably-supported with respect to saidmagnet, a low' impedance coil adapted to be utilized for recording, anda high impedance coil adapted to be utilized for reproduction, said highimpedance coil having suitable electrical characteristics wherebytheihigh impedance coil may 'be substituted for the microphone in areproduction circuit.

ROY DALLY. I 15

